超深气井普遍存在环空持续带压问题，严重威胁油气安全生产。为此，建立了气体流动和传热模型，获取了井筒温度和压力分布。然后，以井筒温度和压力为边界条件，考虑真实气体效应，提出了气体泄漏速率计算方法，并结合环空体积平衡原理，建立了持续套管压力预测模型。最后，通过超深气井现场测试数据验证了预测模型的可靠性。结果表明，绝热系数是气体泄漏速率计算中的关键参数。在真实气体条件下，绝热系数随温度升高而降低、随压力升高而升高；与当前模型相比，基于理想气体的传统方法低估了约22%的质量流量；模型预测值与实测值吻合良好；当环空压力超过最大允许值时，应及时诊断压力来源，并识别泄漏位置与程度。该研究可为超深气井环空带压分析及现场安全管理提供理论指导。

The sustained annular pressure problem is common in ultra-deep gas wells, posing a serious threat to oil and gas production safety. Therefore, a gas flow and heat transfer model was established to obtain the temperature and pressure distribution of the wellbore. Then, using wellbore temperature and pressure as boundary conditions and considering real gas effects, a gas leakage rate calculation method was proposed. Based on the annular volume balance principle, a sustained casing pressure prediction model was developed. Finally, the reliability of the prediction model was verified using field test data from ultra-deep gas wells. The results show that the adiabatic coefficient is a key parameter in gas leakage rate calculations. Under real gas conditions, the adiabatic coefficient decreases with increasing temperature and increases with pressure. Compared to the current model, the traditional method based on ideal gas significantly underestimates the mass flow rate by about 22%. The predicted values agree well with the measured values. When the annular pressure exceeds the maximum allowable value, the pressure source should be diagnosed in time, and the leakage location and extent should be identified. The study provides theoretical guidance for annular pressure analysis and on-site safety management in ultra-deep gas wells.